Multiuser MIMO system, receiver, and transmitter
Even when respective transmitters use different transmission schemes, signals of the respective transmitters are separated. A receiver that is applied to a multiuser MIMO system in which a plurality of transmitters performs transmission to at least one receiver, includes a MIMO separation part 40 that receives signals transmitted in different transmission schemes at the same time and at the same frequency and separates the received signals for each transmitter, a switching part 41 that switches output destinations according to the transmission scheme of the separated signal, and a single-carrier processing part 42 and a multi-carrier processing part 43 provided for each transmission scheme for processing a signal output from the switching part 41 according to its transmission scheme.
1. A multiuser MIMO (Multiple Input Multiple Output) system, the system comprising:
a first terminal device;
a second terminal device; and
a base station device, wherein
the first terminal device is configured to transmit a first transmission signal using a first set of subcarriers and a single-carrier transmission scheme;
the second terminal device is configured to transmit a second transmission signal using a second set of subcarriers and a multi-carrier transmission scheme, where a plurality of subcarriers of the second set of subcarriers is overlapped with a plurality of subcarriers of the first set of subcarriers on a frequency domain; and
the base station device configured to:
receive transmission signals including at least the first transmission signal and the second transmission signal transmitted from the first terminal device and the second terminal device, and
separate the first transmission signal and the second transmission signal from the received transmission signals.
2. A base station device applied to a multiuser MIMO system in which at least a first terminal device and a second terminal device perform transmission to at least the base station device, the base station device comprising:
a reception part configured to receive transmission signals including a first transmission signal and a second transmission signal transmitted from at least the first terminal device and the second terminal device which the first terminal device transmits the first transmission signal using a first set of subcarriers and a single-carrier transmission scheme, and the second terminal device transmits the second transmission signal using a second set of subcarriers and a multi-carrier transmission scheme where a plurality of subcarriers of the second set of subcarriers is overlapped with a plurality of subcarriers of the first set of subcarriers on a frequency domain; and
a MIMO separation part configured to separate the first transmission signal and the second transmission signal from the received transmission signals.
3. The base station device according to claim 2 , wherein
the MIMO separation part is configured to separate from the received transmission signals using an MMSE (Minimum Mean Square Error) weight for each signal received from the first terminal device and the second terminal device.
4. The base station device according to claim 2 , wherein
the MIMO separation part is configured to separate the first transmission signal and the second transmission signal from the received transmission signals using an MMSE (Minimum Mean Square Error) weight.
5. A terminal device that is applied to a multiuser MIMO system in which a plurality of terminal devices perform transmission to at least a base station device, the terminal device comprising:
a transmission part configured to transmit a first transmission signal using a first set of subcarriers and a first transmission scheme which is one of a single-carrier transmission scheme and a multi-carrier transmission scheme, where a plurality of subcarriers of the first set of subcarriers is overlapped with a plurality of subcarriers of a second set of subcarriers on a frequency domain which the second set of subcarriers is used by another terminal device to transmit a second transmission signal using a second transmission scheme differs from the first transmission scheme.
6. The terminal device according to claim 5 , wherein
the first transmission scheme is determined according with a required transmission power.
7. The terminal device according to claim 5 , wherein
the first transmission scheme is one of a transmission scheme to allocate subcarriers contiguously and a transmission scheme to allocate subcarriers discontiguously.
8. The terminal device according to claim 7 , wherein
the transmission scheme to allocate subcarriers contiguously is DFT-S-OFDM transmission scheme and the transmission scheme to allocate subcarriers discontiguously is Clustered DFT-S-OFDM transmission scheme.
9. The terminal device according to claim 5 , wherein
a first PAPR characteristic of the first transmission scheme differs from a second PAPR characteristic of the second transmission scheme.
10. A transmission method of a terminal device constituting a multiuser MIMO system with another terminal device, the transmission method comprising:
transmitting a first transmission signal using a first set of subcarriers and a first transmission scheme which is one of a single-carrier transmission scheme and a multi-carrier transmission scheme, where a plurality of subcarriers of the first set of subcarriers is overlapped with a plurality of subcarriers of a second set of subcarriers on a frequency domain which the second set of subcarriers is used by another terminal device for transmitting a second transmission signal using a second transmission scheme differs from the first transmission scheme.
11. A reception method of a base station device applied to a multiuser MIMO system, the reception method comprising:
receiving transmission signals including a first transmission signal and a second transmission signal transmitted from at least a first terminal device and a second terminal device which the first terminal device transmits the first transmission signal using a first set of subcarriers and a single-carrier transmission scheme, and the second terminal device transmits the second transmission signal using a second set of subcarriers and a multi-carrier transmission scheme where a plurality of subcarriers of the second set of subcarriers is overlapped with a plurality of subcarriers of the first set of subcarriers on a frequency domain; and
separating the first transmission signal and the second transmission signal from the received transmission signals.